High flow miniature proportional control valve with linear moving magnetic voice coil motor

1. A proportional valve comprising: a valve assembly including a valve body that houses a valve operator; the valve body defining an inlet and an outlet for a fluid flow through the valve body; the valve operator having a longitudinal axis and including a poppet that is moveable along the longitudinal axis between a closed position and an open position, wherein in the closed position the poppet seals against a valve seat of the valve body to prevent fluid flow between the inlet and the outlet, and in the open position the poppet is moved away from the valve seat to permit fluid flow between the inlet and the outlet; and an actuator, wherein the actuator comprises an actuator housing that houses: a first magnet element and a second magnet element; a non-magnetic carrier in which the first magnet element and the second magnet element are mounted; a first wire coil located adjacent to the first and second magnet elements, and a second wire coil located adjacent to the first and second magnet elements on an opposite side of the magnet elements relative to the first wire coil; a first spring beam to which the non-magnetic carrier is suspended, the first spring beam being positioned adjacent to the first magnet element, and a second spring beam to which the non-magnetic carrier is suspended, the second spring beam being positioned adjacent to the second magnet element; and a flux frame that conducts magnetic field lines through the actuator; wherein when the wire coils are energized, a magnetic field is generated which causes the non-magnetic carrier to move against the valve operator to move the poppet away from the closed position against the valve seat, thereby opening the valve; and wherein the first and second spring beams are connected to the non-magnetic carrier to control the actuator response to the magnetic field by restraining the movement of the non-magnetic carrier to an arc of sufficient radius that said movement is quasi-linear.

2. The proportional valve of claim 1 , wherein the first and second magnet elements are positioned with their poles opposite each other such that when the wire coils are energized, one magnet element is pulled toward a centerline of the flux frame while the other magnet element is repelled from the centerline of the flux frame.

3. The proportional valve of claim 1 , wherein the non-magnetic carrier has an I-beam shaped cross-section to narrow the magnetic gap for the conduction of the magnetic field.

4. The proportional valve of claim 1 , wherein the first magnet element and the second magnet element are rare earth magnets.

5. The proportional valve of claim 1 , wherein the first spring beam and the second spring beam are made of steel.

6. The proportional valve of claim 1 , wherein the first and second spring beams are directly anchored at one end by an end clamp structure attached to the actuator housing opposite from an end to which spring beams are connected to the non-magnetic carrier, with the spring beams being on opposite sides of the flux frame.

7. The proportional valve of claim 1 , wherein the valve operator further comprises an inlet diaphragm adjacent to the inlet and an outlet diaphragm adjacent to the outlet that pressure balance flow pressures at the inlet and the outlet.

8. The proportional valve of claim 1 , wherein the valve operator further includes a first poppet guide at a first end of the valve poppet, and a second poppet guide at a second end of the valve poppet, which guide movement of the poppet between the closed position and the open position.

9. The proportional valve of claim 8 , wherein the first poppet guide includes a rounded head against which the non-magnetic carrier interacts to move the valve poppet.

10. The proportional valve of claim 1 , wherein the poppet includes a sealing element that seals against the valve seat when the poppet is in the closed position.

11. The proportional valve of claim 10 , wherein the sealing element is an O-ring seal.

12. The proportional valve of claim 1 , further comprising an inlet seal that seals the inlet and an outlet seal that seals the outlet.

13. The proportional valve of claim 12 , wherein the inlet seal and the outlet seal are O-ring seals.

14. The proportional valve of claim 1 , wherein the valve poppet is hermetically sealed from the actuator and from external surroundings.

15. The proportional valve of claim 1 , wherein the valve operator further includes a valve spring that biases the poppet in the closed position.

16. The proportional valve of claim 1 , wherein the spring beams form a triangular shape.

17. A method of calibrating a proportional valve comprising the steps of: providing an actuator, wherein the actuator comprises an actuator housing that houses: a first magnet element and a second magnet element; a non-magnetic carrier in which the first magnet element and the second magnet element are mounted; a first wire coil located adjacent to the magnet elements and a second wire coil located adjacent to the second magnet elements on an opposite side of the magnet elements relative to the first wire coil; a first spring beam to which the non-magnetic carrier is suspended, the first spring beam being positioned adjacent to the first magnet element, and a second spring beam to which the non-magnetic carrier is suspended, the second spring beam being positioned adjacent to the second magnet element; and a flux frame that conducts magnetic field lines through the actuator; providing a valve assembly comprising a valve body defining an inlet and an outlet for a fluid flow through the valve body and a valve operator having a longitudinal axis and including a poppet that is moveable along the longitudinal axis between a closed position and an open position, wherein in the closed position the poppet seals against a valve seat of the valve body to prevent fluid flow between the inlet and the outlet, and in the open position the poppet is moved away from the valve seat to permit fluid flow between the inlet and the outlet; the valve operator further comprises an inlet diaphragm adjacent to the inlet and an outlet diaphragm adjacent to the outlet; setting the actuator housing relative to the valve body to position the actuator housing relative to the valve body with a preload on the spring beams to achieve desired flow and leak performance, the first and second spring beams being connected to the non-magnetic carrier to control the actuator response to the magnetic field by restraining the movement of the non-magnetic carrier to an arc of sufficient radius that said movement is quasi-linear; and positioning components of the actuator within the actuator housing in a manner that maintains the preload at which the desired flow and leak performance are achieved.

18. The method of calibrating a proportional valve of claim 17 , wherein setting the actuator housing comprises pressing the actuator housing against the valve operator to position the actuator housing.

19. The method of calibrating a proportional valve of claim 17 , wherein the first and second spring beams are pre-loaded to optimize positioning of the first and second magnet elements for valve-to-valve performance consistency.